基于链间耦合的并联悬架的刚度优化

Stiffness Optimization of Parallel Suspension based on Inter-chain Coupling

针对越野车辆座椅刚度提升问题,提出了利用并联机构作为座椅悬架主体结构的方案。为保证悬架装置具有高精度位姿和高刚度结构,对链间耦合与固有频率进行研究。首先,通过能量法、虚功原理和扰动理论,可以获得机构的广义质量和广义刚度矩阵;其次,弹性耦合和惯性耦合是基于以上两个广义矩阵而定义的两个指标来测量并联机构的耦合程度,通过Cholesky分解法获得机构的固有频率;然后,为了获得较小的弹性耦合、惯性耦合和较大的固有频率,以固有频率作为目标函数来优化悬架装置的结构参数;最终,对优化结果综合分析,获得最优结构参数用于改进装置结构。

For the improvement of off-road vehicle seat stiffness,a scheme of using parallel mechanism as the main structure of the seat suspension is proposed.The coupling between chains and the natural frequency are studied to ensure that the suspension mechanism has high precision and high stiffness.Firstly,generalized mass and generalized stiffness matrices of the mechanism can be obtained by means of energy method,virtual work principle and disturbance theory.Secondly,elastic coupling and inertial coupling are two indexes defined based on the above two generalized matrices to measure the coupling degree of the parallel mechanism.Cholesky decomposition method is used to obtain the natural frequency of the mechanism.Then,in order to obtain the small elastic coupling,the inertial coupling and a large natural frequency,the natural frequency is used as the objective function to optimize the structural parameters of the suspension mechanism.Finally,the optimization results are comprehensively analyzed and the optimal structural parameters are obtained to improve the structure of the device.